Cylinder honing tools



Jan. 22, 1957 J. T. CLARK 2,778,168

CYLINDER HONING TOOLS Filed Aug. 8, 1955 INVENTOR. Y James T. ClarkATTORNEY 2,778,168 CYLINDER HONINGTOOLS James T. Clark, Fort Morgan,Colo. Application August 8, 1955, Serial No. 527,064 4 Claims. (Cl.51-184.-4)

This invention relates to a device for honing cylinder walls and is moreparticularly designed for use in honing the master brake cylinders ofautomotive vehicles for removing glazed areas from the wall of thecylinder so that a piston will properly seat therein.

The principal object of this invention is to provide a simple compactand highly efficient cylinder 'honing tool which can be mounted in thechuck of an electric drill and which will rotate a plurality of honestones against the cylinder wall to hone the cylindrical surfacethereof.

Another object of the invention is to provide a device of this characterin which the diameter of the circle traveled by the hone stones can beresiliently adjusted so as to accommodate cylinders of various diametersand so as to vary the pressure of the stones against the wall to anydesired degree.

A further object is to so construct the honing tool that the bones willbe diametrically expanded against the cylinder wall by centrifugal forceand to provide highly efiicient cushioning means which will preventdamage to the tool should the latter be accidentally operated beyond theconfining enclosure of the cylinder wall.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efficiency.These will become more apparent from the following description.

I11 the following detailed description of the invention, reference ishad to the accompanying drawing which forms a part hereof. Like numeralsrefer to like parts in all views of the drawing and throughout thedescription.

In the drawing:

Fig. l is a side View of the improved cylinder honing tool;

Fig. 2 is an enlarged longitudinal section through the honing extremityof the tool of Fig. 1;

Fig. 3 is a similarly enlarged cross-section, taken on the line 33, Fig.2; and

Fig. 4 is a similarly enlarged cross section, taken on the line 44, Fig.2.

The improved cylinder honing tool is designed to be rotated in itsentirety about its longitudinal axis from any motor driven device suchas an electric drill and is provided with a chuck stud designed to bechucked in the chuck of such a drill.

The chuck stud is formed with an axial socket for receiving the rearextremity of a length of flexible shaft 11. The shaft extremity ispermanently clamped in its socket by crimping the stud thereabout asindicated at 12.

The forward extremity of the length of flexible shaft 11 is permanentlycrimped, as indicated at 13, in an axial receiving socket formed in theouter extremity of a tool shaft 14. The forward extremity of the toolshaft 14 terminates in an axial threaded stud 15 of reduced diameter.

A spider hub 16 is threaded onto the threaded stud 15 against a shoulder17 formed by the reduction in diameter of the stud 15. The spider hub isprovided with three States Patent radially projecting attachment cars 18each of which is drilled to receive a fulcrum rivet 19.

A hone arm 20 is pivotally mounted on each fulrum rivet 19 and extendsforwardly therefrom. The hone arms 20 are 'channehshaped in crosssection and the two sides formed by the channel shape of each arm extendon opposite sides of the adjacent attachment ear 18 and are pivotallysecured thereto by the fulcrum rivet 19.

A h is tiltably secured on the portions on each member 21 which extendon :opposite sides of the hone arm at the hinge rivets '22.

An elongated hone stone 23 is cemented to each hone frame member bymeans of any suitable adhesive of a type which is moisture and oilresistant.

A lever portion 24 projects rearwardly from each hone arm 20. The leverportions 24 of the three hone arms 20 The lever portions 24 extend intoa conical, concentric cavity 26 formed in a cone member 27 which islongitudinally slidable on the shaft 14. The cone member '27 isconstantly urged toward the lever portions 24 by means of a compressionspring 28 surrounding the shaft 14. The forward extremity of the spring28 is frictionally fitted over a spring receiving sleeve 29 formed onthe cone member 27.

The rear extremity of the spring 28 is received in a spring receivingcavity 30 which is concentrically formed in the forward face of aknurled adjusting nut 31 which is threaded on suitable threads 32 formedon the shaft 14.

In use, the chuck stud 10 is placed in the chuck of 11 electric drilland the adjusting nut 31 is threaded rearwardly to relieve thecompression in the spring 28 so that the resilient washer '25 can forcethe lever portions 24 outwardly. The outward movement of the leverportions acts against the conical surface of the cavity 26 to force thecone member 27 rearwardly and to bring the hone stones 23 toward eachother so as to decrease the honing diameter.

The hone stones honed,

cone member 27 forwardly so that its internal conical surface will actagainst the lever radially inward. This, of course, acts to force thehone stones radially outward causing them to resiliently engage the wallof the cylinder.

The drill is now started and the hone stones are whirledcircumferentially within the cylinder under the centrifugal expansiveforce of rotation. As they rotate, they are moved longitudinally of thecylinder to hone the cylinder surface and remove any glazed portionstherefrom. The pressure of the hone stones against the cylinder wall canbe accurately regulated by varying the position of the nut 31. However,the hone stones can be compressed together at any time without varyingthe position of the nut 31, due to the resiliency of the spring 2.8.

Should the tool be accidentally pulled from the cylinder, centrifugalforce will tend to expand the hone stones relative to each other. Thisoutward expanding action, however, will not damage the tool due to thecushion action of the resilient washer 25 against the lever portions ofthe arms.

Since the hone stones 23 and their supporting structures are all similarand equal in weight, the centrifugal action of all will be equal so thatthe tool will be automatically centered in the cylinder by centrifugalforce. The drill need not be accurately centered due to the flexibilityof the flexible shaft 11. a

While a specific form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried, within the scope of the appended claims, Without departing fromthe spirit of the invention.

Having thus described the invention what is claimed and desired securedby Letters Patent is:

1. A cylinder honing tool comprising: a shaft; a spider hub secured onthe forward extremity of said shaft; a plurality of cars projectingradially from said spider hub; a hone arm hingedly mounted on each earand extending forwardly therefrom; a hone element tiltably mounted onthe forward extremity of each hone arm; a lever secured to each hone armand projecting rearwardly from the hinge point thereof; a resilientlycompressible disc-like member surrounding said shaft and positionedbetween said shaft and said levers and acting in consequence of itsinherent resiliency to urge said levers outwardly so as to urge saidhone elements radially inward; and adjustable means for urging saidlever inwardly against said compressible member.

2. A cylinder honing tool as described in claim 1 in which the lattermeans for urging comprises: a cone member having a conical concavity inwhich the extremities of said levers are received, said cone memberbeing longitudinally movable on said shaft; a compression springsurrounding said shaft rearwardly of said cone member; and a nutthreaded on said shaft and acting when rotated in one direction tocompress said spring against said conical member.

3. A cylinder honing tool comprising: a shaft; a spider hub secured onthe forward extremity of said shaft; a plurality of ears projectingradially from said spider hub; a hone arm hingedly mounted on each earand extending forwardly therefrom; a hone element tiltably mounted onthe forward extremity of each hone arm; a lever secured to each hone armand projecting rearwardly from the hinge point thereof; a resilientlycompressible disc-like member surrounding said shaft and positionedbetween said shaft and said levers and acting in consequence of itsinherent resiliency to urge said levers outwardly so as to urge saidhone elements radially inward; a cone member having a conical concavityin which the extremities of said levers are received, said cone memberbeing longitudinally movable on said shaft; and means for urging saidcone member toward said levers to cause the conical wall of said cavityto urge said levers inwardly against said compressible member.

4. A cylinder honing tool comprising: a shaft; a spider hub secured onthe forward extremity of said shaft; a plurality of ears projectingradially from said spider hub; a hone arm hingedly mounted on each earand extending forwardly therefrom; a hone element tiltably mounted onthe forward extremity of each hone arm; a lever secured to each hone armand projecting rearwardly from the hinge point thereof; a resilientlycompressible disc-like member surrounding said shaft and positionedbetween said shaft and said levers and acting in consequence of itsinherent resiliency to urge said levers outwardly so as to urge saidhone elements radially inward; a cone member having a conical concavityin which the extremities of said levers are received, said cone memberbeing longi tudinally movable on said shaft; means for urging said conemember toward said levers to cause the conical wall of said cavity tourge said levers inwardly against said compressible member, said lattermeans for urging comprising a compression spring surrounding said shaftrearward of said cone member; and a nut threaded on said shaft andacting, when rotated in one direction, to compress said spring againstsaid conical member.

References Cited in the file of this patent UNITED STATES PATENTS1,474,649 Storm No 20, 1923 1,567,417 Campbell Dec. 29, 1925 1,647,133Jennings Nov. 1, 1927 2,083,685 Burk-halter June 15, 1937 2,112,120Schmidt Mar. 22, 1938 FOREIGN PATENTS 68,080 Netherlands June 15, 1951

